1. Field of the Invention
The present invention relates to a waterproof assembly, and more particularly to a waterproof assembly for sealing an opening of a case of an electronic device.
2. Related Art
A portable electronic device for being operated outdoor, such as a rugged laptop computer, is often sprayed by water occasionally under adverse circumstances. Therefore, a portable electronic device or a rugged laptop computer must be waterproof, so as to preventing water from entering the interior of the device to short the electronic components and to damage the device.
Generally, water entering a portable electronic device occurs in two ways. For one way, a case of the portable electronic device is combined by a plurality of members, so that slits may be generated on junctions between adjacent members, and thus water may run through the slits. For the other way, openings must be opened in the case, for disposing electrical connectors and sockets, such that water may run through the openings, the electrical connectors, and the electrical sockets.
Accordingly, waterproof implementation on the junctions between the members on the case aims at reducing tolerance of the members, enhancing a junction force between the members, such that the junctions between the members are more tightly fitted. An adhesive, seal ring, foaming material or the like is filled in the junctions, so as to eliminate any possible slit, thereby preventing the water from entering through the junctions. Different water-absorbent filling materials are introduced in the art. For example, compounds as disclosed in U.S. Pat. No. 5,852,077 and U.S. Pat. No. 5,075,373, are further filled in the pores where water leakage may occur, so as to absorb and block the water, thereby preventing the water from entering the case. Furthermore, as disclosed in ROC Patent Publication No. 200722963, a water absorbent member is fixed on an inner side of the case, so as to further absorb the water accidentally entering into the case, thereby protecting the electronic device from being damaged by the water once a waterproofing function of the case fails. However, the above waterproofing implementation is semi-permanent, and the waterproofing implementation will failed when the case is dismounted.
For the connectors, sockets, and the openings corresponding to the connectors and the sockets, the aforementioned semi-permanent waterproofing implementation cannot be applied at all. The openings are opened whenever necessary, so as to enable external electrical contactors to be connected to the connectors and sockets of the electronic device. The waterproofing implementation on an opening is to seal the opening with a cover, and the cover body is removed when the opening is required to be opened.
Referring to FIG. 1, in the prior art, a cover body 2 used to seal an opening 1 is shown. An elastic ring 3 is fitted to an outer peripheral surface of the cover body 2. When the cover body 2 is placed into the opening 1, the elastic ring 3 is pressed against an inner wall of the opening and is deformed, so as to block the water from passing through the gap between the outer peripheral surface of the cover body 2 and the inner peripheral surface of the opening 1.
Referring to FIG. 2, another cover body 5 used to seal an opening 4 in the prior art is shown. The cover body 5 is made of elastic material, and an outer diameter thereof is larger than an inner diameter of the opening 4. When the cover body 5 is placed into the opening 4, the cover body 5 is compressed and deformed, so as to closely contact an inner wall of the opening 4 to block the water from passing through the gap between the outer peripheral surface of the cover body and the inner peripheral surface of the opening 4.
In FIGS. 1 and 2, when the cover bodies 2 and 5 are not properly mounted (for example, the cover bodies are not mounted on correct positions), or the element made of an elastic material is broken, the water still runs through the gaps between the cover bodies 2 and 5 and the openings 1 and 4, so as to directly result in a short circuit of the electrical connectors or the sockets, and further damage the electronic device when water enters the case.
In addition, the waterproofing effect depends on a contact pressure among the elastic sleeve ring 3, the cover body 5, and the openings 1 and 4. When a large contact pressure is provided, the waterproofing effect is improved. However, if a large contact pressure is provided, the difficulty for mounting and dismounting the cover bodies 2 and 5 is increased, and the elastic sleeve ring 3 or the cover body 5 made of the elastic material is easily broken. If the contact pressure is small, the waterproofing effect is distinctly poor. Therefore, it becomes a technical problem how to modify the waterproofing measures on the electrical connection ports and corresponding openings when the rugged laptop computer and other portable electronic devices are fabricated.